DataNode communicate with NameNode
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how DataNode communicate with NameNode and some internal structure of NameNode
DataNode communicate with NameNode
- 2. Protocol ? register: handshake,register when startup ? heartbeat: liveness,capacity,used,remaining. short time 3s default ? blockreport: diff. long time 6h Protocol
- 3. Inside NameNode ? FSNameSystem : INode,Metadata ? BlockManager:Block,DataNode,Heartbeat ? 两者关系不是割裂，紧密联系
- 4. Inside NameNode ? DataNode在NameNode中对应的对象 ? DataNode ——> DataNodeDescriptor ? Disk ——> DataNodeStorageInfo ? Block在DataNodeStorageInfo中以List存储，头结 点为blockList
- 5. INode ? Dir —> INodeDirectory只有meta，没有实际存储 ? File —> INodeFile Blocks Replica
- 6. INodeFile ? INodeFile存储BlockInfo ? BlockInfo存储triplet : save memory, block report
- 7. Heartbeat ? the function of heartbeat
- 8. BlockReport ? The function of BlockReport
- 9. BlockReport ? toInvalidate:不在BlockMap中，该Block已经被删 除 ? toUC:在BlockMap中，状态为UC ? toCorrupt:在BlockMap中，状态为Corruput ? toAdd:在BlockMap中，triplet没有该节点的该磁 盘 ? toRemove:没有汇报，丢失的Block
- 10. 叠濒辞肠办搁别辫辞谤迟流程
- 11. BlockReport
- 12. BlockReport